Micofabricated Cantilever-Based Scanner for forward-looking 3D Endoscopic Optical

描述（由申请人提供）：该项目旨在开发一种新型二维光学扫描仪，以实现内窥镜前视 3D 光学相干断层扫描。内窥镜 OCT (EOCT) 通过“光学活检”提供了微创诊断的潜力，该“光学活检”包括多种组织中的原位断层扫描亚表面成像。基于导管的 EOCT 是通过放置在内窥镜内的导管传输光束来进行的。导管 OCT 探头采用侧视几何形状开发，适用于窄腔血管成像。前瞻探头将大大增强对胃、结肠和膀胱等大型或中空器官的粘膜成像的能力，但由于导管尺寸的限制，实施起来很复杂。实现前瞻性 EOCT 的方法已有报道，由于在小导管直径 (2.9 mm) 内插入二维光学扫描仪很困难，因此通常提供单维扫描。考虑到导管集成的二维光学扫描仪，可以使用位于内窥镜外部的参考光束的纵向尺寸扫描来获得高分辨率 3D EOCT 成像。这种成像方法将能够对癌症和其他病变进行准确的非侵入性诊断，这些病变的穿透深度仅限于上皮或近上皮下层。 这里提出的二维光学扫描仪的新颖设计基于微加工悬臂。静态偏转和共振频率计算表明，对于一组合理的参数，所提出的方案比竞争方法具有尺寸和功耗优势以及出色的扫描范围和速度性能。该项目专注于针对导管 OCT 成像优化的二维扫描仪的微加工和表征。微加工处理步骤将被设计为包括根据执行器几何形状和薄膜厚度对扫描性能的计算影响而选择的一系列参数。设备的机械和光学特性将通过一套可用的测量工具来表征。将根据光学扫描仪的实际性能对EOCT系统进行详细的光学模拟。优化后的设备将与合适的光学元件集成，并集成到高速傅里叶域 OCT 扫描仪中以评估图像质量。

DESCRIPTION (provided by applicant): This project aims at the development of a novel two-dimensional optical scanner to enable endoscopic forward-looking 3D Optical Coherence Tomography. Endoscopic OCT (EOCT) provides the potential for minimally invasive diagnostics by "optical biopsy" consisting of tomographic sub-surface imaging in situ in a variety of tissues. Catheter-based EOCT is performed by delivering the light beam through a catheter placed inside an endoscope. Catheter OCT probes have been developed using a side-looking geometry, which is appropriate for imaging narrow-lumen vessels. A forward-looking probe would greatly enhance the ability of imaging mucosa of large or hollow organs such as stomach, colon, and bladder, but the implementation is complicated by the catheter size constraints. Approaches to achieve forwardlooking EOCT have been reported and typically offer uni-dimensional scanning due to the difficulty of inserting a two-dimensional optical scanner within the small catheter diameter (2.9 mm). Given a catheter-integrated, two-dimensional optical scanner, high resolution 3D EOCT imaging can be obtained using longitudinal dimension scanning with the reference beam located outside the endoscope. This imaging approach will allow accurate non-invasive diagnoses of cancers and other pathologies limited in depth of penetration to epithelial or near sub-epithelial layers. The novel design for the two-dimensional optical scanner proposed here is based on microfabricated cantilevers. Static deflection and resonance frequency calculations indicate that, for a reasonable set of parameters, the proposed scheme provides a size and power consumption advantage over the competing approaches and excellent scanning range and speed performance. This project is focused on the microfabrication and characterization of a two-dimensional scanner optimized for catheter OCT imaging. The microfabrication processing steps will be designed to include a range of parameters selected based on the calculated effects of actuator geometry and film thicknesses on scanning performance. The mechanical and optical properties of the devices will be characterized with a suite of available measurement tools. A detailed optical simulation of the EOCT system will be performed based on actual performance of the optical scanner. Optimized devices will be integrated with suitable optical components and incorporated into a high-speed Fourier-Domain OCT scanner to assess image quality.